Increase SMTP security (MTA-STS and TLS)
1. Check your MTA-STS configuration
Skip this step if your domain has never used MTA-STS
If your domain has never used MTA-STS, skip this step and go to Create an MTA-STS policy.
Before you set up MTA-STS for Gmail, check current the MTA-STS configuration for your Gmail domains. You can see which domains do not have a configuration, or have an invalid configuration.
This feature is available with G Suite Enterprise, Cloud Identity Premium, G Suite Enterprise for Education, and G Suite for Education.
Check your domain MTA-STS configuration
You must be signed in as an administrator for this task. Learn more about admin privileges for the security center.
- Go to Security > Security Health.
- From Security Health, go to MTA-STS.
- The MTA-STS configuration status for your G Suite domains is in the Status column:
- Correctly configured: The domain has a valid MTA-STS configuration.
- Configured for all domains: All domains have a valid MTA-STS configuration.
- Missing or misconfigured: One or more domains do not have an MTA-STS configuration, or have an invalid configuration.
- For missing or invalid configurations, click the domains link in the status message to see which domains have a missing or invalid MTA-STS configuration.
Note: The MTA-STS health check displays only one issue at a time for each domain, even if the domain has more than one issue. Add or fix the MTA-STS issue to resolve the issue, then run the security health check again to see any other issues.
Add or fix an MTA-STS configuration
To add or fix a configuration for one or more domains, go to Create an MTA-STS policy.